New types of communication systems have been constructed, implemented, and popularly-utilized as a result of advancements in communication technologies. In various of the new types of communication systems, the rate of data transmission and the corresponding amount of data permitted to be communicated through their use has increased relative to existing types of communication systems.
New types of radio communication systems are exemplary of communication systems that have been made possible as a result of advancements in communication technologies. Communication channels of a radio communication system are formed upon air, i.e., radio, links, thereby obviating the need for conventional wire line connections between sending and receiving stations operable in a radio communication system. Increased communication mobility, relative to a conventional wire line system, is provided, as a result, in a radio communication system. A cellular communication system is an exemplary type of radio communication system.
Amongst the advancements in communication technologies are advancements in digital communication techniques. Increasingly, communication systems utilize digital communication techniques in communication operations by which data is operated upon to facilitate its communication during operation of the communication system. The use of digital communication techniques, for instance, permits improvement in the bandwidth efficiency of communications in a communication system which utilizes the digital communication techniques. Because of the particular need in a cellular, or other radio, communication system to efficiently utilize the spectrum allocated thereto, the use of digital communication techniques is particularly advantageously implemented therein.
When digital communication techniques are used, information that is to be communicated is digitized. In one technique, the digitized information is formatted into packets, and the packets are communicated to effectuate the communication. Individual ones, or groups, of the packets of data can be communicated at discrete intervals. And, once communicated, the packets can be concatenated together to recreate the informational content contained therein.
Because packets of data can be communicated at the discrete intervals, a communication channel need not be dedicated solely for the communication of packet data generated by one sending station for communication to one receiving station, in contrast to conventional requirements of circuit-switched communications. Instead, a single channel can be shared amongst a plurality of different sending and receiving station-pairs. Packet data communications are effectuated in both conventional wire line communication systems, such as in conventional LANs (local area networks) as well as in radio communication systems.
Various constructions of cellular communication systems provide for packet data communications. And, various cellular communication system standards have been promulgated in which operational standards related to packet data communications are set forth for the cellular communication systems constructed according to such standards.
A cellular communication system is implemented throughout a geographic area by positioning a plurality of fixed-site, base transceiver stations throughout an area in which the communication system is to be installed. Each of the base stations defines a coverage area, referred to as a cell, within which radio communications with a mobile station are possible.
The base stations are controlled by cell gateways (CGWs), and the cell gateways are connected to a base station gateway (BSGW). The base stations, cell gateways, and base station gateways are collectively referred to as the network portion, network infrastructure, or radio access network (RAN) of the communication system. A mobile station is used to communicate, by way of an air link, with a selected base station. Because a cellular communication system is a multi-user communication system, a plurality of concurrent communication sessions in which packet data flows are communicated with more than one mobile station regularly occur.
The air links upon which packet data flows are communicated to effectuate communication with mobile stations are susceptible to various environmental, and other, conditions. Distortion of values of portions of data packets of the packet data flow during their transmission upon the air link might prevent their successful delivery to the mobile station. Retransmission of the adversely-affected data packets is sometimes, therefore, required. When excessive amounts of retransmissions are necessary, congestion conditions result. Too many data packets become “backed up” awaiting successful communication and then must be discarded. In a congestion condition, the packet data flow is unable successfully to be effectuated.
Routing of data packets of the packet data flow through the radio access networks consumes communication resources—both processing capacity of the network and communication bandwidth capacity. If the data packets are merely going to be discarded due to poor communication conditions on the air link, routing of the packet data flow through the radio access network ends without successful effectuation of communication with the mobile station, and the communication resources of the radio access networks are not efficiently utilized. The communication resources could better be utilized to facilitate communication of other packet data flows of other communication sessions.
A manner by which selectably to alter packet data flows in a radio access network of a radio communication system in the event that air link conditions are unacceptable would permit better utilization of the communication resources of the radio access network and thereby permit improved communication system operation.
It is in light of this background information related to packet radio communication systems that the significant improvements of the present invention have evolved.